code: def decode_schema(j_str: str) -> Dict[str, SchemaField]:
      schema_dict = json.loads(j_str, object_hook=as_enum)
      schema = {}
      for k, v in schema_dict.items():
          schema[k] = SchemaField.from_dict(v)
      return schema
  
imports: from collections import namedtuple
  from io import BytesIO
  import numpy
  from itertools import chain, islice
  from enum import Enum
  import json
  from bigdl.dllib.utils.log4Error import *
  from typing import Any, Dict, Iterator, List, Union, TYPE_CHECKING
label_desc: Use image node_id 4 for calling a global function with example usage: decode_schema(j_str) and returns: schema